A planetary system 116 light-years from Earth has a peculiar pattern. It could flip the script on how planets form, scientists say.

Astronomers have spotted an unusual 'inside-out' planetary system where a rocky world seems to have formed far beyond the realm typically reserved for gas giants.

Gas giants are large planets mostly composed of helium and/or hydrogen. Although these planets have dense cores, they don't ...

Pluto was reclassified as a dwarf planet in 2006. Our solar system may have a ninth planet after all, researchers say. The possibility that an additional planet may be hidden far into the solar system ...

When you see art of our solar system as the planet orbit the sun, you may notice that Earth's orbit has a tilt. It is not a perfect circle. What's more, Earth is not the only planet that displays such ...